Any current vision of the future of immersive experience revolves around ambient imagery, ephemeral indicators, on-demand content built on a technology stack that includes a light-field-based system of pixels. For a menu to float off a wall or a billboard to float off the side of a building, the imagery must accommodate viewers from different angles. To make a holodeck or deliver on some other architecture of light, the user must have a display system that delivers content perceived as 3D and that provides real parallax, vergence, and accommodation to viewers across a range of different positions relative to the display. The system must do this regardless of whether that viewer wears glasses. The system must do this from any arbitrary point in the room without barrel rotation, a fault that causes each viewer to perceive an object in a slightly different location because of limits within legacy 3D systems.
There is no current screen that effectively manages light field display across an arbitrary surface in a way that is commercially scalable and that delivers effective extinction or ghosting of other viewing angles.
LCD derivatives used for small displays and displays are currently in the market and they use parallax barrier systems to deliver multiple angles of light with projected or direct view sources.
The Philips® 3D LCD system handles this by dicing the screen area up with a lenticular lens that divided the surface of the LCD into a defined number of slices so that a viewer could see a 3D image from a specific set of points of view but there was little opportunity for a shared experience without eye tracking and the experience will always be limited by the need to slice up the image area in vertical slices.
The Leia® display shares some characteristics with the display that Nintendo® delivered in the Nintendo 3DS®. The displays are optimized around a single user with a display right and left eye.
There are a variety of large modules being considered and there are complicated parallax barrier systems that treat existing displays in a manner that is not dissimilar to the Philips 3D system.
These monolithic systems will all have trouble scaling into room scale immersive environments. These systems also often have bezels that will figure in any final product marring the finished displays with seams that must be managed or tolerated. They are targeted at individual viewers and the market for smartphones is massive so this makes sense commercially.
But that means that none of these systems lends itself to use in large public display applications where a flexible modular approach will be required to jump start applications and to take advantage of existing mechanical systems.
One solution is to model the components on LED systems that have adopted the PLCC SMD package to allow for a wide variety of products. But there is an issue with using a large array of LEDs where the viewer is only intended to view a specific set of sub-pixels at a given time based on their location relative to the screen.
First, the relative surface area of each sub-pixel relative to the complete component would yield a very small active area. The light emitting elements in a 2 mm pixel pitch screen in the current LED market may be less than a few percentage points of the total surface area of a pixel. In a light field display packing hundreds of pixels into the same space the output power of that pixel required to maintain perceived screen brightness would jump substantially, and in some ways, unhelpfully.
Second, a mask is required to control the light output so that each viewer only sees the light field sub-pixel intended for them. This mask would create pixels with substantial off axis viewing issues and would likely create visual artifacts due to the incomplete extinction of neighboring light field sub-pixels.
Third, the duty cycle for each light field sub-pixel is small relative to the overall number of LED packages It would be possible to use multiplexing to use ⅓ the LED dies simplifying layout and reducing cost. It is also possible to use ⅕ or ⅛ the LED material depending on the goals of the system.
There are more problems, but the number of dies and the extinction issue are key. If a user cannot see just the image intended for them but also sees ghosting from the images intended for other people (the extinction ratio) then the technology will not succeed.